Control device



P. S. JACKSON Oct. 16,1951

CONTROL DEVICE 4 Sheets-Sheet 1 Paul Filed Oct. 25, 1948 P. S. JACKSONOct. 16, 1951 CONTROL DEVICE 4 Sheets-Sheet 2 Filed 001:. 23, 1948 Oct.16, 1951 5. JACKSON 2,571,886

CONTROL DEVICE Filed Oct. 23, 1948 4 Sheets-Sheet 5 IIIIIIIIIII P. S.JACKSON Oct. 16, 1951 CONTROL DEVICE 4 She ets-Sheet 4,

Filed Oct. 23, 1948 INVENTOR.

Patented Oct. 16 1951 U N I TED S TATE S PAT EN'T O F F I -CE CONTROLDEVICE Application October 23, 1948, Serial .No. 56,134

19 Claims.

This invention relates to control mechanisms and more particularly to .acontrol mechanism for a reciprocating member.

It is a general object of this invention to producea controldevice for areciprooatingmember.

'It is a more specific object of this invention to produce a device for.controlling .the length of stroke of a reciprocating member.

It is va further .objectof this invention to produce .a device forcontrolling the stroke of a hydraulically .reciprocated member whereunequal volumes of fluid are moved with reciprocation in each direction.

.It is a further objectof this invention to pro- .duce a control deviceaccording to any of the precedingparagraphs which isreadily adjustable.

Yet another objectoi the invention is to produce .a control devicehaving a control panel on which are located .adjllstable means forcontrolling the volume of fluid for reciprocating a member andjhavingindicating means associated with the panel .forvisuallyindicating the setting of theadjustable means.

.Another .and further objects of the invention will be apparent-from thefollowing description .and drawings in which:

Fig. .1 is .a diagrammatic view of the control .and the hydrauliccircuit;

.Fig. .2 is.a front feleva'tional viewof .the-con- .trol .panel with the.face vremoved;

Fig. .3 is a sectionalong line ,3.3 of Fig.2;

Fig. .4 .is a view like Fig. .2 with .the faceof the panel .in .place;

Eig. 5-is .asectionalview along,line.5,-i.5 of Fig. 4;

,Fig; 6 is a .detailedsectional view of .thevolume control for the pump;.and

; Fig. 7 is an elevational view of ,the .entire. control "panel.

While vmy invention is susceptible of embodi- .-mentmany-different;for1ns,-l haveshown the drawings and willhereindescribein-detail onesuch embodiment, aWith the understanding .thatflthe presentdisclosure -is to be considered -as an exemplificationof.the principIe of them- 'vention and isgnot-intendedto limititheinvention to the embodiment illustrated. iI'he scope of:thezinvention -will:.-be;pointed. out in-.the appended -.c1aims.

-.For1the ,purpose= of exemplary a disclosure J ,h.ave .chosen .to:describe any invention as-used. inconjunction with -,anzexerciser-forexercisingathe -recoil mechanism of a gun, although itwill ,be

gapparentifrom:the disolosure thatithe devicermay yhe ,used-.tocontrol--.the gstro k e. of .any-.rec iprocating idevice. r

Referring vnow to Fig. l of the drawings I show a reversible, variabledelivery hydraulic pump L0 which may be reversed in the usual mannerthrough energization of solenoids H and 12. The volume of fluid moved ineither direction by the pump may be regulated by regulating means I3 andM which last-named means may be controlled by knobs l5 and i6 mountedupon a control panel to be later described, which panel bears aninscribed dial H. The knobs are connected to their respective volumecontrol devices by rotatable rods [8 and I9.

Interposed in the hydraulic circuit is a fourway hold-up valve 2E1having a casing 2! and a longitudinal bore 22 in the casing. 'Slidableinthe bore is a spool valve device 23. The valve casing is provided withthree parts, 24, "25 and 2E on one side thereof and a single port 2,! onthe other side. The spool valve 23 is slidable longitudinally in thebore and is urged 'ina clos- Ling direction by spring 28. A solenoiddevice 29 is adapted to operate a valve mechanism 30 to permit pilotpressure to shift the valve 23 longitudinally in .the casing to openposition a ainst the tension of the spring 28. The bore is provided witha passage 31 connecting with annular grooves 32 .and 33 and is alsoprovided with annular grooves 34,, '35 and '36. The valve 20 has but twopositions, the on position as .shown in Fig. l .and an off position inwhich .all ports .are blocked.

Also located in the hydraulic circuit is adif- ,terential relief valve33,0 which pomprises aoasing 4! having a bore '42 therein. A spool valve43 ,is .slidable longitudinally in the boreand urged -toward movement,in one direction by a spring .45. The valve Jill is provided with three.ports 45, .45 and .47 on one sideoi the casing, a single iport 4.8 .onthe other .side of jtheoasing', and a portifiii enteringdirectly to theborej5'2. A port gen .is. .a1so;provided at one end ,of the bore forpurposes to be hereinafter described.

" Withthe .parts in theposition shown inFig. l

hydraulic iluid under pressure from the pump .IB is directed into thecylinder line conduit '5i .and enters .the'boretZthrough thepor @149.The .fluid passes by the .spool valve A3 and into a Passage.5.2.inthevalveyifl to conduit "53. From .icondnit 153 fluid is directedinto .a' hydraulic metering motor .5 4 which 4 motor is rotated by .theaction of fluid passing therethrouglrand transmits that rotation bymeans of shaft -5 -.c.oup ng flann l sp r ducer :5 t a sha -;58connected ..to a control tilevice 59.. I prefer 55..

to use a :hydraulic metering .motor of the type shown when apparatus,is. used inthe. manner illustrated wherein portability of the entiredevice is essential. However, where the control device is to be usedwith a, reciprocating member which is fixed in position, for example, ason a machine tool, I may use a rack and pinion device or other motormeans connected directly to the reciprocating member to rotate the shaft58.

From the metering motor, cylinder line fluid passes into a conduit 65and enters the port 25 of valve 20. The fluid passes along the bore 32,into the annular groove 35 and out port 26 to a conduit 6!. The conduit6i connects with a conduit 62 and thence directly into the cylinder E3in which the reciprocating member is located to reciprocate the memberin one direction. Also connected to the conduit 62 is a bleeder valve 54and a pressure gauge 55. The conduit 62 also opens to the bore 42 ofvalve 40 through the port and fluid pressure against the plunger 56'secured to the spool valveserves to urge the spool valve 43 to theposition shown.

Removably attached to the other end of the cylinder 63 is a hydraulicjack 64 having a member adapted to bear against the rod 65 connected tothe reciprocating member. It is understood that the rod 65 is normally apart of the recoil mechanism of the gun. Fluid returning from the jackE4 enters the jack line 66 in which bleeder valves Bi and pressure gauge68 are located and passes along the conduit 59 and into the port 24 ofthe valve 2:). The fluid thence passes along annular groove 34 into thepassage 3] and thence into the conduit 10 by means of the port 27. Theconduit 10 is connected to a conduit Tl which leads into the port 12 ofpump l0 and also is connected to the valve 40.

As the volume of fluid pumped by the pump 10 exceeds the volume returnedfrom the hydraulic jack 54, means are provided for making up thedifference between the volumes. Accordingly, I provide a make-up pump I3driven by the same means as drives the pump [0 and make-up fluid issupplied into the conduit 14 having a pressure gauge 15 connectedtherewith and thence into the valve mechanism 38 for shifting the spoolvalve 23 in accordance with the position of the solenoid 29. Make-upfluid is also supplied directly to the conduit 16 which is connected toa conduit i7 and port 4! of valve 40. With the valve in the positionshown,

make-up fluid may enter the port 41, pass along the annular groove l!and bore 42 and into the conduit H through the port 45.

When the reciprocating member in the cylinder 53 reaches the end of itsstroke my control device hereinafter to be explained serves to reversethe pump Hl. With the pump l0 reversed, fluid under pressure reversesits direction in the line ii and passes through the means just describedinto the jack line 66. Fluid returning from the cylinder line throughconduit 62 reverses its direction through the valve 28 and the meteringmotor 54 to rotate the motor the same number of revolutions as when thecircuits Were reversed, but in the opposite direction. As suction isapplied to the line 62 the spool 43 of valve 40 is shifted upward (asshown in Fig. l) to block off ports 46 and 41 and prevent jack linepressure from the pump Hi from entering the make-up circuit. Port 49 isalso blocked and port 45 is connected with the passage 52 so that allhydraulic fluid returning from cylinder 63 through valve and motor 54line 53 is directed through port 45, 52 and bore 42 to port 45 into theconduit 88 connected to 4 the tank or sump. With the valve in thisposition, pump suction is through a pipe and check valve (not shown),but incorporated in the pump.

My control device contemplates means for energizing the solenoids H andI2 to reverse pump Hi When the reciprocating member in the cylinder 63reaches the end of its stroke in each direction. Accordingly, the shaft58 which is rotated by the metering motor is mounted in r a housing 8!and terminates in a reduced portion 82 extending beyond the face of adial 83. A hollow shaft 84 is frictionally secured to the portion 82 andsimilarly extends beyond the face of the dial 83 and terminates in aknob-like portion 85. A spring 86 is positioned between a shoulderportion 8! of the knob 85 and a cap 88 on the end of the shaft 82 tourge the shaft 84 and 82 to rotate together. The spring just describedconstitutes a part of a clutch member whereby the shaft 84 may berotated independent of the rotation of the shaft 82.

Fixed to the shaft 84 is a spur gear 89 meshing with a second spur gear90 fixed upon a control shaft 91 rotatably mounted in the housing 8!.The control shaft BI is mounted in bear ings 92 and 93 and is urgedtoward downward movement (as shown in Fig. 3) by a spring 94, thedownward movement causing an extension 85 of the gear 90 to bear againstthe end of a collar portion 96 secured in the housing. A pointer 91 issecured to the outer end of the control shaft 9| and exterior to thepanel 83.

Rotatably mounted on the Collar portion 96 is a spur gear 98 whichmeshes with an idler ear 99 mounted upon shaft I00 in the housing. Theidler gear 99 meshes with a gear Illl mounted upon shaft I02. The shaftI02 is rotatably mounted in the housing and carries a second gear H33meshing with an internal gear 104 rotatably mounted in the housing 8|.The internal gear carries a pointer I which is moved with rotation ofthe gear I04 across the face of the dial panel. The dial 83 is suitablyinscribed with figures indicating the number of cubic inches of fluidnecessary to effect reciprocation of the member and rotation of the gearIE4 is adapted to move the pointer I05 across the inscribed face of thedial visually to indicate the volume of fluid to be pumped at anyparticular setting of the pointer. A control knob 10B is mounted uponthe end of the shaft Hi2 and may be manually rotated to rotate theinternal gear lbs and the spur gear 98.

A control arm H8 is rigidly fixed to the control shaft 9! and oscillatedwith reversing rotation of the shaft 9 I. The outer end of the controlarm carries a bearing Ill adapted to depress a limit switch H2 mountedin the housing to energize one of the solenoids and effect reversal ofthe pump Ill. The spur gear 98 is provided with a device in the form ofa bolt H3 which extends into the path of oscillation of the con trol armH0. Reversal of the pump by contact of the control arm H0 with the limitswitch H2 causes the control arm to oscillate in the opposite directionand bring the bearing 1 l I into contact with the device H3. Such acontact serves to move the control shaft 9| longitudinally of its axisof rotation and against a second limit switch 4 to energize the othersolenoid and again to reverse the pump 10.

The position of the device H3 in the path'of oscillation of the controlarm is, of course, dependent upon the position of the gear 98- and thegear may be rotated by means of the knob I I36 through the gears NH and99, as previously described.

Actuation of the limit switch I I4 can be performed manually at any timeby inward pressure of the pointer 91 to reverse the motor II].

It is clear that by rotation of the knob I08 the pointer I85 is movedalong the scale of the dial until the desired volume of flow in thecylinder line is indicated, the volume, of course, being determined bythe volume of fluid necessary to reciprocate the device in the cylinder63 through a full stroke in one direction. Simultaneously with movementof the pointer I05 the device H3 is moved either toward or away from thelimit switch H2 in the plane of the path of oscillation of the controlarm 'I In to determine the amount of oscillation Of that arm necessaryto effect successive reversal of the pump. The actual speed ofreciprocation of the member and cylinder 63 is, of course, determined bythe setting of the volume controls on the pump I!) but regardless of thespeed of reciprocation my control device serves to effect reversal ofthe pump at the desired point in the stroke of the reciprocating member.

The inscribed dials I7 and 83 are mounted upon a control panel I20 Whichalso carries the gauges 65, 63 and I5 and knobs I5, I6, 85 and I06. Theshafts I8 and I9 are rotatably mounted on the panel, the rod I8 beingconnected directly to the volume control I3 while the rod I 9 isconnected to the volume control I4 through a series of spur gears I2I,I22 and I23 rotatably mounted in housing I2 5. Secured to the controlpanel I29 is a housing I25 in which a pair of ring gears I26 and I2! arerotatably mounted, the ring gear I26 meshing with a spur gear I28 fixedto the shaft I8 and the ring gear I21 meshing with a spur gear I29 fixedto the shaft I9. The ring gear I21 carries a pointer I38 movable aroundthe dial I1 and the ring gear I2! carries a second pointer I 3|similarly movable around the dial. Rotation of the knob I5 which, forexample, may be the volume control for the cylinder line, serves throughthe gears just mentioned not only to control the operation of the volumecontrol I3 but also to move the pointer I3I over the inscribed face ofthe dial I! to indicate the volume of fluid moved by the pump in onedirection. The pointer I36 associated with the jack line controlindicates the volume moved by the pump through the jack line.

I claim:

1. A stroke-control apparatus for a recip-rocable member comprisingreversible means for reciprocating the member, means for reversing thereversible means, a motor driven in forward and reverse in synchronismwith the reciprocation of the member, a control shaft oscillated by themotor, actuating means for the reversing means, means for operating theactuating means carried by the control shaft and adapted to operate theactuating means at the end of an oscillation of the control shaft in onedirection to reverse the reciprocating means, a device extending intothe path of oscillation of the operating 'meansi'n theother directionand adapted to operate'tlie operating means upon contact with theoperating means again to reverse the reciprocatin'g means, and manuallyoperable setting means for "selectively moving the device to variouspoints in the cating the member, means for reversing the reversiblemeans, a motor driven in forward and reverse in synchronism with thereciprocation of the member, a control shaft oscillated by the motor,actuating means for the reversing means, means for operating theactuating means carried by the control shaft and adapted to operate theactuating means at the end of an oscillation of the control shaft in onedirection to reverse the reciprocating means, a device extending intothe path of oscillation of the operating means in the other directionand adapted to operate the opcrating means upon contact therewith againto reverse the reciprocating means, manually operable Setting means forselectively locating the device at various points in the path ofoscillation of the operating means and manually operable means foroscillating the control shaft independent of the motor.

'3. A stroke-control apparatus for a 'reciproc'a ble member comprisingreversible means for reciprocating the member, means for reversing thereversible means, a motor driven in forward and reverse in synchronismwith the reciprocation of the member, a control shaft oscillated by themotor, actuating means for the reversing means, means for operating theactuating means carried by the control shaft and adapted to operate theactuating means at the end of an oscillation of the control shaft in onedirection to reverse the reciprocating means, a device extending intothe path of oscillation of the operating means in the other directionand adapted to operate the operating means upon contact therewith againto reverse the reciprocating means, manually operable setting means forselectively moving the device to various points in the path ofoscillation of the operating means, a graduated control panel, andindicating means operated by the setting means to indicate on the panelthe location of the device.

4. A stroke-control apparatus for a reciproca- -ble member comprisingreversible means for reciprocating the member, means for reversing thereversible means, a motor driven in forward and reverse in synchronismwith the reciprocationoi the member, a control shaft oscillated by themotor, actuating means for the reversing means, means for operating theactuating-means carried by the control shaft and adapted to operate theactuating means at the end of an oscillation of the control shaft in onedirection to reverse the reciprocating means, a device extending intothepath of oscillation of the operating means in the other direction andadapted to operate the operating means upon contact therewith again toreverse the reciprocating means, manually operable setting means forselectively moving the device to various points in the path ofoscillation of the operating means, a graduated control panel,indicatingmeans operated by the setting means to indicate on the panel the lobythe control shaftandadapted-to operate-the actuating means at the end ofan oscillation of the control shaft in one direction to reverse thereciprocating means, a device extending into the path of oscillation ofthe operating means in the other direction and adapted to operate theoperating means upon contact therewith again to reverse thereciprocating means, manually operable setting means for selectivelymoving the device to various points in the path of oscillation of theoperating means, a graduated control panel, indicating means operated bythe setting means to indicate on the panel the location of the device, apointer on the panel aligned with the operating means and oscillated bythe control shaft to indicate on the panel the position of the operatingmeans, and manually operable means on the panel for oscillating thecontrol shaft independent of the motor.

6. A stroke-control apparatus for a reciprocable member comprisingreversible means for reciprocating the member, means for reversing thereversible means, a motor driven in forward and reverse in synchronismwith the reciprocation of the member, a control shaft oscillated by themotor, actuating means for the reversing means, means for operating theactuating means carried by the control shaft and adapted to operate theactuating means at the end of an oscillation of the control shaft in onedirection to reverse the reciprocating means, a device extending intothe path of oscillation of the operating means in the other directionand adapted to operate the operating means upon contact therewith againto reverse the reciprocating means, manually operable setting means forselectively moving the device to various points in the path ofoscillation of the operating means, a graduated control panel, a pointermovable around the panel, a knob on the panel mounted on a rotatablesetting shaft, a first gear on the setting shaft for moving the pointerand a second gear on the setting shaft for moving the device to variouspoints in said path.

7. A stroke-control apparatus for a reciprocable member comprisingreversible means for reciprocating the member, means for reversing thereversible means, a motor driven in forward and reverse in synchronismwith the reciprocation of the member, a control shaft oscillated by themotor, actuating means for the reversing means, means for operating theactuating means carried by the control shaft and adapted to operate theactuating means at the end of an oscillation of the control shaft in onedirection to reverse the reciprocating means, a rotatably mounted gear,a device mounted on the rotatable gear and extending into the path ofoscillation of the operating means in the other direction and adapted tooperate the operating means upon contact therewith again to reverse thereciprocating means, a graduated control panel, a pointer mounted on aninternally toothed gear and movable around the panel, a knob on thepanel mounted on a rotatable setting shaft, a first gear on the settingshaft meshing with the internal gear and a second gear on the shaft forrotating the gear carrying the device.

8. In combination with a reciprocable member and electrically reversiblemeans for reciprocating the member, a control device for thereciprocating means comprising a housing, a control shaft rotatablymounted in the housing and oscillated in synchronism with reciprocationof the member, a pair of limit switches in the housing for reversing thereciprocating means, a control arm carried by the shaft and adapted tooperate one of said switches at the end of an oscillation of the controlarm in one direction, a device extending into the path of oscillation ofthe control arm in the other direction and adapted to cause operation ofthe other switch upon contact of the control arm therewith, and manuallyoperable setting means for selectively moving the device to variouspoints in the path of oscillation of the control arm.

9. In combination with a reciprocable member and electrically reversiblemeans for reciprocating the member, a control device for thereciprocating means comprising a housing, a control shaft rotatablymounted in the housing and oscillated in synchronism with reciprocationof the member, a pair of limit switches in the housing for reversing thereciprocating means, a control arm carried by the shaft and adapted tooperate one of said switches at the end of an oscillation of the controlarm in one direction, a gear in the housing rotatably mounted about theaxis of rotation of the control shaft, a device carried by the gear andextending into the path of oscillation of the control arm in the otherdirection and adapted to cause operation of the other switch uponcontact of control arm therewith, a setting shaft rotatably mounted inthe housing, and a gear mounted on the setting shaft for rotating thegear carrying the device for selectively moving the device to variouspoints in the path of oscillation of the control arm.

10. In combination with a reciprocable member and electricallyreversible means for reciprocating the member, a control device for thereciprocating means comprising a housing, a control shaft rotatablymounted in the housing and oscillated in synchronism with reciprocationof the member, a pair of limit switches in the housing for reversing thereciprocating means, a control arm carried by the shaft and adapted tooperate one of said switches at the end of an oscillation of the controlarm in one direction, a gear in the housing rotatably mounted about theaxis of rotation of the control shaft, a device carried by the gear andextending into the path of oscillation of the control arm in the otherdirection and adapted to cause operation of the other switch uponcontact of the control arm therewith, a graduated control panel on thehousing, a pointer movable around the panel and carried by an internallytoothed gear rotatably mounted in the housing, a knob on the panel andmounted on a rotatable setting shaft, a first gear on the setting shaftmeshing with the internally toothed gear, and a second gear on thesetting shaft for rotating the gear carrying the device, rotation of theknob being adapted to move the device to various points in the path ofoscillation of the control arm and simultaneously to move the pointeraround the panel.

11. In combination with a reciprocable member and electricallyreversible means for reciprocating the member, a control device for thereciprocating means comprising a housing, a control shaft rotatablymounted in the housing, means for oscillating the control shaft insynchronism with reciprocation of the member, a pair of limit switchesin the housing for reversing the reciprocating means, a control armcarried by the shaft and adapted to operate one of said switches at theend of an oscillation of the control arm in one direction, a gear in thehousing rotatably mounted about the axis of rotation of the controlshaft, a device carried by the gear and extending into the path ofoscillation of the control arm in the other direction and adapted tocause operation of the other switch upon contact of the control armtherewith, a graduated control panel on the housing, a pointer movablearound the panel and carried by an internally toothed gear rotatablymounted in the housing, a knob on the panel mounted on a rotatablesetting shaft, a first gear on the setting shaft meshing with theinternally toothed gear, a second gear on the setting shaft for rotatingthe gear carrying the device, rotation of said setting shaft beingadapted to move the device to various points in the path of oscillationof the. control arm and to move the pointer around the panel, a driveshaft interposed between the oscillating means and the control shaft andclutch means for rotating the drive shaft to oscillate the control shaftindependent of the oscillating means.

12. In combination with a reciprocable member and electricallyreversible means for reciprocating the member, a control device for thereciprocating means comprising a housing, a control shaft rotatablymounted in the housing and movable therein longitudinally of its axis ofrotation, means urging the control shaft toward movement in onelongitudinal direction, means for oscillating the control shaft insynchronism with reciprocation of the member, a pair of limit switchesin the housing for reversing the reciprocating means, a control armcarried by the shaft and adapted to contact one of the said switches atthe end of an oscillation of the control arm in one direction, a deviceextending into the path of oscillation of the control arm in the otherdirection and adapted to contact the control arm to move the shaftlongitudinally in the housing in the other direction and into operatingcontact with the other switch, a graduated control panel on the housing,a pointer movable around the panel and carried by an internally toothedgear 1 rotatably mounted in the housing, a knob on the panel and mountedon a rotatable setting shaft, a first gear on the setting shaft meshingwith the internally toothed gear, a second gear on the setting shaft, anidler gear meshing with the second gear and meshing with the gearcarrying the device, rotation of said setting shaft being adapted tomove the device to various points in the path of oscillation of thecontrol arm and to move the pointer about the panel.

13. In a combination with a reciprocable member and electricallyreversible means for reciprocating the member, a control device for thereciprocating means comprising a housing, a control shaft rotatablymounted in the housing and movable therein longitudinally of its axis ofrotation, means urging the control shaft toward movement in onelongitudinal direction, means for oscillating the control shaft insynchronism with reci rocation of the member, a pair of limit switchesin the housing for reversing the reciproeating mea s, a control armcarried by the shaft and adapted to contact one of the said switches atthe end of an oscillation of the control arm in one direction, a deviceextending into the path of oscillation of the control arm in the otherdirection and adapted to contact the control arm to move the shaftlongitudinally in the housing in the other direction and into operatingcontact with the other switch, a graduated control panel on the housing,a pointer movable around the panel and carried by an internally toothedgear rotatably mounted in the housing, a knob on the panel and mountedon a rotatable setting shaft, a first gear on the setting shaft meshingwith the internally toothed gear, a second gear on the setting shaft,anidler gear meshing with the second gear and meshing with the gearcarrying the device, rotation of said setting shaft being adapted tomove the device to various points in the path of oscillation of thecontrol arm and to move the pointer about the panel, a drive shaftinterposed between the oscillating means and the control shaft andgeared to the control shaft and clutch means on the control panel forrotating the drive shaft to oscillate the control shaft independent ofthe oscillating means.

1 4. In combination with a reciprocable member and electricallyreversible means for reciprocating the member, a control device for thereciprocating means comprising a housing, a control shaft rotatablymounted in the housing and movable therein longitudinally of its axis ofrotation, means urging the control shaft toward movement in onelongitudinal direction, means for oscillating the control shaft insynchronism with reciprocation of the member, a pair of limit switchesin the housing for reversingthe reciprocating means, a control armcarried by the shaft and adapted to contact one of the said switches atthe end of an oscillation of the control shaft in one direction, adevice extending into the path of oscillation of the control arm in theother direction and adapted to contact the control arm to move the shaftlongitudinally in the housing in the other direction and into operatingcontact with the other switch, a graduated control panel on the housing,a pointer movable around the panel and carried by an internally toothedgear rotatably mounted in the housingja knob on the panel and mounted ona rotatable setting shaft, a first gear on the setting shaft meshingwith the internally toothed gear, a second gear on the setting shaft, anidler gear meshing with the second gear and meshing with the gearcarrying the device, rotation of said setting shaft being adapted tomove the device to various points in the path of oscillation of thecontrol arm and to move the pointer about the panel, and a secondpointer on the panel mounted on the end of the control shaft and alignedwith the operating means to indicate on the panel the position of theoperating means, manual pressure on said second pointer being adapted tomove the control shaft longitudinally against the urging means tooperate said other switch.

15. In a hydraulic circuit including a reversible pump and means forcontrolling the volume of fluid moved by the pump in forward and inreverse, a control comprising a control panel, a graduated dial on thepanel, pointers movable around the dial a knob rotatably mounted on thepa el an connec d t a o n er a d to o of the volume control means, asecond knob rotatably mounted on the panel and connected to anotherpointer and to the other volume control means, rotation of a knob beingadapted to operate a volume control means and to move a pointer on thedial, a second graduated dial on the panel, a third pointer movablearound the second dial, adjustable means mounted on the panel forreversing the pump and a third knob rotatably mounted on the panel andconnected to the third pointer and to the reversing means, rotation ofthe third knob being adapted to move the reversing means for controllingthe operation thereof and to move the third pointer on the second dial.

16. In a hydraulic circuit including a reversible pump, a controlcomprising a control panel, a graduated dial on the panel, a pair ofring gears rotatably mounted on the panel concentric with the dial, apointer on each gear and movable around the dial, a pair of shaftsrotatably mounted on the panel, a spur gear on each shaft meshing with adifferent one of said ring gears, means for controlling the volume offluid moved by the pump in forward and means for controlling the volumeof fluid moved by the pump in reverse, each of said shafts beingconnected to a different one of said volume control means, wherebyrotation of each of said shafts is adapted to operate the volume controlmeans connected thereto and to move a pointer around the dial.

17. In a hydraulic circuit including a reversible pump, a controlcomprising a control panel,

a graduated dial on the panel, a pair of ring gears rotatably mounted onthe panel concentric with the dial, a pointer on each ring gear andmovable around the dial, a pair of shafts rotatably mounted on thepanel, a spur gear on each shaft meshing with a different one of saidring gears, means for controlling the volume of fluid moved by the pumpin forwardand means for controlling the volume of fluid moved by thepump in reverse, each of said shafts being connected to a different oneof said volume control means; whereby rotation of each of said shafts isadapted to operate the control means connected thereto and to move apointer around the dial, a second graduated dial on the panel, a thirdpointer movable around the second dial, a first'gear carrying the thirdpointer. adjustable means for reversing the pump, a second gear foradjusting the reversing means, a third shaft rotatably mounted on thepanel, a third gear carried by the third shaft and meshing with thesecond gear,a fourth gear on the third shaft meshing with the first gearcarrying the third pointer, whereby rotation of said third shaft isadapted to adjust the reversing means and to move the third pointer onthe second dial.

18. In a hydraulic circuit including a reversible pump, and a meteringmotor driven by the pump, a control comprising a control panel, agraduated dial on the panel, a pair of ring gears rotatably mounted onthe panel concentric with the dial, a pointer on each gear and movablearound the dial, a pair of shafts rotatably mounted on the panel, a spurgear on each shaft meshing with a different one of said ring gears,means for controlling the volume of fluid moved by the pump in forwardand means for controlling the volume of fluid moved by the pump inreverse, each of said shafts being connected to a volume control means,whereby rotation of said shafts is adapted to operate the volume controlmeans connected thereto and to move a pointer around the dial, a secondgraduated dial on the panel, a third pointer movable around the seconddial, a control shaft oscillated by the motor, a control arm mounted onthe control shaft and carrying means for reversing the pump,

around the dial,

an externally toothed gear rotatably mounted on the panel, means foroperating the reversing means carried by the last-mentioned gear, aninternally toothed gear rotatably mounted on the panel and carrying thethird pointer, a third shaft rotatably mounted on the panel and carryinga first gear meshing with the externally toothed gear and carrying asecond gear meshing with the internally toothed gear, whereby rotationof said shaft is adapted to move the operating means and to move thethird pointer on the second dial.

19. In a hydraulic circuit including a reversible pump, and a meteringmotor driven by the pump, a control comprising a control panel, agraduated dial on the panel, a pair of ring gears rotatably mounted onthe panel concentric with the dial, a pointer on each gear and movable apair of' shafts rotatably mounted on the panel, a spur gear on eachshaft meshing with a different one of'said ring gears, means forcontrolling the volume of fluid moved by the pump in forward and meansfor controlling the volume of fluid moved by the pum in reverse, each ofsaid shafts being connected to a different one of said volume controlmeans, whereby rotation of said shafts is adapted to operate the volumecontrol means connected thereto and to move a pointer around the dial, asecond graduated dial on the panel, a third pointer movable around thesecond dial, a control shaft oscillated by the motor, a control armmounted on the control shaft and carrying means for reversing the pump,an externally toothed gear rotatably mounted on the'panel, means foroperating the reversing means carried by the last-mentioned gear, aninternally; toothed gear rotatably mounted on the panel and carrying thethird pointer, a shaft rotatably mounted on the panel, a first gear onthe last-mentioned shaft meshing with the externally toothed gear, asecond gear on the last-mentioned shaft meshing with the internallytoothed gear, rotation of said last-mentioned shaft being adapted tomove the operating means and to move the third pointer on the seconddial,'a second shaft rotatably mounted on the panel and connecting thecontrol shaft with the motor and means for rotating the second shaft tooscillate the control arm independent of the motor.

PAUL S. JACKSON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,156,433 Pratt Oct. 12, 19152,191,552 Zimmerman Feb. 27, 1940 2,259,587 Rush g Oct. 21, 1941

